Shark attack is a long recognized problem faced by divers and surfers as well as recreational ocean swimmers. A variety of devices are known that include electrical, mechanical, and chemical techniques for warding off a shark attack.
Chemical techniques are dependant on both the particular formulation of the shark repelling substance and the method or device for delivering the substance into the aquatic environment. A common shark repelling substance is anhydrous sodium sulfate mixed in equal parts by volume with sodium laurel sulfate. To be effective, the substance must not only be an effective repellant, it must also be released at an appropriate time prior to an attack and have sufficient persistence to outlast a shark's patience.
An example of a shark repellant delivery system is disclosed in U.S. Pat. No. 4,602,384 to Schneider, wherein a full body suit is covered with pockets containing a chemical repellant. However, the repellant is not dispersed into the water until a shark nibbles on the suit. This configuration of this system is predicated on the assumption that a shark will not start its meal with a big bite.
Another shark repellant delivery system is disclosed in U.S. Pat. No. 4,917,280 to Schneider, wherein a liquid permeable belt is provided with cells containing chemical repellant capsules, each capsule having a different time-delay coating. The configuration of the belt allows water to enter the cells the instant the belt is immersed in the water. Although such an arrangement provides a steady dispersal of chemical repellant into the water, a wearer is unable to delay the moment of dispersal, making it unsuitable for a diver or surfer who might not encounter a shark immediately upon entry to the water.
Yet another delivery system is disclosed in U.S. Pat. No. 4,816,260 to Wollrich, wherein a capsule containing repellant is mounted on a stiff, but flexible, support. Bending the support ruptures the capsule and disperses the repellant into the environment. Although such an arrangement allows for the repellant to be dispersed on demand, the necessary rigidity of the support does not lend itself to applications wherein it would be preferable to have a compliant support, such as a wrist or ankle band. Additionally, the technique required to burst the capsule is incompatible with applications wherein it would be preferable to affix the device to a wetsuit or other article of scuba gear to provide ready access to the device.
In view of these limitation of the prior art with respect to the needs of swimmers, surfers and divers, it would be desirable to provide a conveniently wearable, easily opened, delivery system for a chemical shark repellant.